Saving visible edge overlay as separate layer

Hi, I have read through some of the old threads, regarding saving the "lines layer" of a luxology render when using visible edge overlay. but I am still having trouble saving the visible edges as a separate layer. I can see the visible edges in the luxology dialog, and I can save the image together with the visible edges. But when saving my image to a psd file. I am not getting separate layers out, just the merged image. What am I doing wrong?

As I recall it was much easier in earlier versions?

Thanks, Brian